When scientists examined a sample of wild Pacific salmon from Alaska—including Chinook salmon, pink salmon, rainbow trout, and sockeye salmon— they found larva of Diphyllobothrium nihonkaiensen in the muscles of the pink salmon. Previously, this parasite was only known to infect fish in Asia, Food Safety Magazine reports.

This type of tapeworm, known as the Japanese broad tapeworm, is a common cause of a condition called diphyllobothriosis, which can result in diarrhea or abdominal pain.

The researchers say that this shows that salmon caught anywhere on the Pacific Coast of North America may be infected.

If the fish is not frozen during transport, the parasites may be able to enter your body and make you sick. So, if you intend to eat fish raw, like in sushi, the FDA says the fish should be frozen first. The Alaska Seafood Marketing Institute says the vast majority of Alaska salmon is frozen.

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